Electric thermal window with an adjustable terminal structure

ABSTRACT

1. A THERMAL WINDOW COMPRISING A GLASS PANE, A HEATING GRID INCLUDING A BUS BAND AFFIXED TO THE GLASS PANE, AND A TERMINAL HAVING SPACED PORTIONS FIXEDLY ATTACHED TO THE BUS BAND AT SPACED POINTS, THE TERMINAL INTERMEDIATE THE FIXED POINTS OF ATTACHMENT BEING FREE OF ATTACHMENT TO THE GLASS PANE AND THE BUS BAND AND CAPABLE OF EASY CHANGE IN DIMENSION IN RESPONSE TO EXTERNAL STIMULI, SAID TERMINAL HAVING A STRAP PORITION ATTACHED TO SAID SPACED PORTIONS AND AN INTERMEDIATE PART WHICH IS OFFSET FROM THE SPACED PORTIONS, THE WIDTH OF THE BUS BAND BEING GREATER THAN THE WIDTH OF THE SPACED PORTIONS OF THE TERMINAL ATTACHED THERETO, AND IN WHICH THE TERMINAL LIES PARALLEL TO THE EDGE OF THE GLASS PANE, IS ATTACHED TO THE BUS BAND BY SPACED ARMS AND HAS A CONTACT ATTACHED TO THE OFFSET PART OF THE STRAP PORTION EXTENDING PARALLEL TO THE EDGE OF THE GLASS PANE.

Jan. 7, 1975 H. o. PEETZ ETAL Re. 28,295

ELECTRIC THERHAL WINDOW WITH A" LDJUSTABLE TERHINAL STRUCTURE OriginalFiled Sept. 14, 1970 a shuts-suit 1 INVENTORJ IVA/V5 D/Efifi PEEIZ AER/44! All/RS561 5% MM ATTO NEYS ELECTRIC THERMALWINDDW WITH All LDJUSTABLETERIINAL STRUCTURE Original Filed Sept. 14. 1970 Jan. 7, 1975 H. o.PEETZ ETAL 2 Shula-Shut 2 INVENTORS IVA/VS D/ETER PEEI'Z BY //RM4AM/ZURSSEIV ATTOR United States Patent 76,1 Int. Cl. HOSb 3/06 US. Cl.219-522 14 Claims Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by reissue.

ABSTRACT OF THE DISCLOSURE A thermal window having a glass pane, anelectrical heating grid including bus bands afiixed to the glass pane,and flat terminals having spaced portions fixedly attached to the busbands at spaced points. The terminal intermediate the fixed points ofattachment being free of attachment to the glass pane and the bus bandand capable of easy change in dimension in response to external stimuli.

This application is a continuation of our application Ser. No. 666,795,filed Sept. 11, 1967, and now abandoned.

This invention relates to the construction of thermal windows (cf.French Pat. No. 1,464,585) and particularly t0 the assemblage of thepane, the heating grid, and the terminal. As the thermal window isuseful in automobilesto prevent fogging, icing and other accumulations,the description will proceed with that structure in view as exemplary.

I Thermal windows, of the type improved by this invention, have a glasspane which in automobiles is plain, triplex, or tempered, to one face ofwhich a heating grid is attached as illustrated in FIG. 5. The grid maybe resistance metal or resistance composition, may be in various formseither truly grid or so termed by courtesy, the shape, type, and methodof attachment to the glass being part of the prior art unnecessary to bedescribed here. In general, such windows have bus bands extending acrossopposite edges of the glass, between which extend the heatingresistances.

1 Electrical terminals are very sensitive to the effects of changes intemperature, strong strains forming parallel to the glass because oftheir differences in coefficients of expansion, frequently detaching theterminal from the glass and sometimes cracking its outer surface, ineither case making it useless.

We have discovered the cause of this imperfection and have corrected itby this invention. The invention involves a thermal window comprising aglass pane, a heating grid including a bus band affixed to the glass,and a terminal fixedly attached to the bus band and to the glass atspaced points, the terminal intermediate the fixed points of attachmentbeing free, of attachment to the glass and the bus band, and capable ofeasy change in dimension in response to external stimuli.

The above and further objects and novel features of the presentinvention will more fully appear from the following detailed descriptionwhen the same is read in connection with the accompanying drawings. Itis to be expressly understood, however, that the drawings are for thepurpose of illustration only and are not intended as a definition of thelimits of the invention.

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In the drawings, wherein like reference characters refer to like partsthroughout the several views,

FIG. 1 is a perspective view of a portion of a thermal window of thesimplest form according to this invention;

FIG. 2 is a plan view, partly in section, of the connection between theterminal and the grid and glass;

FIG. 3 is a perspective view of an improved form of the invention;

FIG. 4 is a perspective view of another form of the invention; and

FIG. 5 is a perspective view of the preferred form of the invention.

In FIG. 1 the window pane 1 bears an aflixed heating grid 23 the bars 2of which extend between bus bands 3, only one of which is shown. Thebars and bands are of some known construction mounted on the pane byknown methods. The electrical terminals are constructed of flat plates5, 6, 7 shaped like the letter B, the central limb of which is extendedat 8 to form a Contact to which the contact of the lead will beattached, e.g. as in FIG. 4. In this novel construction the limbs 5, 6are alone attached to the grid and the glass, the method of attachmentbeing that used in the prior art, and the areas of attachment 11, 12(FIG. 2) are small and are spaced apart. This leaves the length of theplate or strap portion of the terminal between 11, 12 free in the senseof being unattached to the glass, and the length of such portion is ofsmall width, as provided by the spaces between the limbs of the E, whichreduces the strength of the terminal and allows it to yield under thediffering atmospheric conditions encountered in seasons and storms. Wehave also discovered that the total width of limbs 5 and 6 mayadvantageously be less than the width of the bus band by an amount A(FIG. 1). In a terminal of copper or brass of about 0.5 mm. thicknessthe distance A may be on the order of 0.5 to 1 mm.

An advantageous form of the invention is illustrated in FIG. 3 whereinthe central or strap part 13 of the terminal is offset at 14, 1.5 fromthe pane and the bus band, furnishing a readily deformable connection,between the points of attachment, capable of yielding readily tostresses imposed by temperature change or other conditions of operation.

The forms of FIGS. 1 to 3 have a projecting contact 8 which causesframing problems, but these have been overcome in FIGS. 4 and 5. In FIG.4 the offset 13 is projected at 14 and 15 over and parallel to the edgeof the pane, the part 15 being flush against but not attached to thepane and the contact 16 being displaced enough from the pane to seat thecooperating contact 18.

The preferred form of the invention shown in FIG. 3 has the plate 5',6', 13' parallel to the edge of the pane, two tabs 21, 22 are bent overthe edge of the pane and soldered to the bus band 3, and two contacts23, 24 which are the ends of a single band attached at its middle to theoffset strap 13'. This construction is recessed (25, 25) in the side ofthe pane so that all problems of framing are eliminated. A similarreduction at the end of the pane of FIG. 4 accomplishes a like result.

These new constructions yield readily to externally applied pressure,spare the connections and the pane, reduce the stresses caused by changein temperature and different rates of expansion, and eliminate thefailures caused by prior constructions. The problems of framing, andelimination of projections capable of suffering shock are solved.

As many apparently widely different embodiments of the present inventionmay be made without departing from the spirit and scope thereof, it isto be understood that the invention is not limited to the specificembodiments.

What is claimed is:

l. A thermal window comprising a glass pane, a heating grid including abus band alfixed to the glass pane, and a terminal having spacedportions fixedly attached to the bus band at spaced points, the terminalintermediate the fixed points of attachment being free of attachment tothe glass pane and the bus band and capable of easy change in dimensionin response to external stimuli, said terminal having a strap portionattached to said spaced portions and an intermediate part which isoffset from the spaced portions, the width of the bus band being greaterthan the width of the spaced portions of the terminal attached thereto,and in which the terminal lies parallel to the edge of the glass pane,is attached to the bus band by spaced arms and has a contact attached tothe offset part of the strap portion extending parallel to the edge ofthe glass pane.

2. A thermal window comprising a glass pane, a heating grid including abus band afiixed to the glass pane, and a terminal having spacedportions fixedly attached to the bus band at spaced points, the terminalintermediate the fixed points of attachment being free of attachment tothe glass pane and the bus band and capable of easy change in dimensionin response to external stimuli, in which the terminal has a strapportion attached to said spaced portions thereof, and at least a part ofthe strap portion is offset and overlies and is parallel to the edge ofthe glass pane and is provided with a contact parallel to the edge ofthe glass pane.

3. A thermal window comprising a glass pane, a heating grid including abus band affixed to the glass pane, and a terminal having spaced portionfixedly attached to the bus band at spaced point, the terminalintermediate the fixed points of attachment being free of attachment tothe glass pane and the bus band and capable of easy change in dimensionin response to external stimuli, the said glass pane having a recess ina portion of its outline, and the terminal is disposed in said recess.

4. A thermal window comprising a glass pane, a heating grid including abus band affixed to the glass pane, and a terminal having spacedportions fixedly attached to the bus band at spaced points, the teminalintermediate the fixed points of attachment being free of attachment tothe glass pane and the bus band and capable of easy change in dimensionin response to external stimuli, in which the terminal has a strapportion attached to said spaced portions and the strap portion has anintermediate part which is otfset from the spaced portions, the bus bandoverlying and extending along a broad surface of the glass pane adjacentan edge thereof, the strap portion overlying the edge of the glass pane,and the spaced portions of the terminal comprise angular elements onearm of each of which overlies the edge of the glass pane and is attachedto the respective end of the strap portion, and the other arm of whichoverlies and is attached to the bus band.

5. A thermal window according to claim 4, in which the glass pane has arecess in a portion of its outline, and the terminal is disposed in saidrecess.

6. A thermal window according to claim 5, comprising a contact attachedto the strap portion of the terminal, and the contact is disposed insaid recess.

7. In a thermal window comprising a glass pane and a heating gridtherefor, including a bus band fixed to and extending along an edgeportion of the glass pane, the

improvement comprising, an elongated terminal plate hav- 5 ing endportions spaced and interconnected by an intermediate portion, saidintermediate portion being oflset .4 from said end portions and capableof easy change in dimension in response to external stimuli, at leastone of said end portions being spaced from both ends of said bus band,said end portions only being directly and fixedly attached to said busband at locations spaced longitudinal- 1y therealong to eliminatedestructive strain resulting from external stimuli, and electricalcontact means connected with said intermediate portion.

8. The thermal window of claim 7, said intermediate portion being bowedupwardly out of contact with the underlying bus band.

9. The thermal window of claim 7, said contact means comprising a strapintegrally connected at one end with said intermediate portion andextending, first outwardly parallel with the glass pane, across thecontiguous edge thereof, then downwardly and transversely across saidcontiguous edge, to terminate in a contact extending parallel with thecontiguous edge of the glass pane.

10. The thermal window of claim 9, said intermediate portion being bowedupwardly out of contact with the underlying bus band.

11. The thermal window of claim 7, each said end pot tion comprising afirst tab and a second tab integral with said first tab and extendingdownwardly over and trans versely across the contiguous edge of theglass pane, said first tabs only being aflixed to said bus band atlocations spaced therealong, said intermediate portion integrallyconnecting said second tabs only, and extending longitudinaily along andin overlying relation with, the contiguous edge of the glass pane.

12. The thermal window of claim 11, said intermediate portion beingbowed outwardly out of contact with and spaced from the underlying edgeof the glass pane.

13. The thermal window of claim 12, and a contact band secured to saidintermediate portion centrally thereof, and extending generally parallelwith the adjacent edge of the glass pane, said second tabs, intermediateportion, and contact band lying within a recess in the contour of thepanes edge.

14. Current lead-in means for a thermal window comprising a glass paneand a heating grid including a bus band secured to the glass pane, saidlead-in means comprising, s flat metallic plate having end portionsspaced and integrally interconnected by an intermediate portion, saidend portions only being directly and fixedly attached to said bus bandat areas spaced therealong, and electrical contact means connected withsaid intermediate portion only.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS 2,787,693 4/1957 Razlag 339256 SP 2,795,682 6/1957Knoll 219-543 X 2,861,168 11/1958 Knoll 219345 X 2,954,454 9/1960 Gaiser219--203 2,965,874 12/1960 Modrey 339-258 S 2,977,450 3/1961 Boicey219541 3,379,859 4/1968 Marriott 219-522 VOLODYMYR Y. MAYEWSKY, PrimaryExaminer US. Cl. X.R.

2l9203, 543; 338-309, 316; 339-9 E, 258 S

